Path parameters

Query parameters

An optional request ID to identify requests. Specify a unique request ID so that if you must retry your request, the server will know to ignore the request if it has already been completed.

For example, consider a situation where you make an initial request and the request times out. If you make the request again with the same request ID, the server can check if original operation with the same request ID was received, and if so, will ignore the second request. This prevents clients from accidentally creating duplicate commitments.

The request ID must be a valid UUID with the exception that zero UUID is not supported (00000000-0000-0000-0000-000000000000).

Name of the resource. Provided by the client when the resource is created. The name must be 1-63 characters long, and comply with RFC1035. Specifically, the name must be 1-63 characters long and match the regular expression [a-z]([-a-z0-9]*[a-z0-9])? which means the first character must be a lowercase letter, and all following characters must be a dash, lowercase letter, or digit, except the last character, which cannot be a dash.

description

string

An optional description of this resource. Provide this property when you create the resource.

target

string

URL of the managed instance group that this autoscaler will scale.

Authorization requires the following Google IAM permission on the specified resource target:

compute.instanceGroupManagers.use

autoscalingPolicy

object

The configuration parameters for the autoscaling algorithm. You can define one or more of the policies for an autoscaler: cpuUtilization, customMetricUtilizations, and loadBalancingUtilization.

If none of these are specified, the default will be to autoscale based on cpuUtilization to 0.6 or 60%.

autoscalingPolicy.minNumReplicas

number

The minimum number of replicas that the autoscaler can scale down to. This cannot be less than 0. If not provided, autoscaler will choose a default value depending on maximum number of instances allowed.

autoscalingPolicy.maxNumReplicas

number

The maximum number of instances that the autoscaler can scale up to. This is required when creating or updating an autoscaler. The maximum number of replicas should not be lower than minimal number of replicas.

autoscalingPolicy.coolDownPeriodSec

number

The number of seconds that the autoscaler should wait before it starts collecting information from a new instance. This prevents the autoscaler from collecting information when the instance is initializing, during which the collected usage would not be reliable. The default time autoscaler waits is 60 seconds.

Virtual machine initialization times might vary because of numerous factors. We recommend that you test how long an instance may take to initialize. To do this, create an instance and time the startup process.

autoscalingPolicy.cpuUtilization

object

Defines the CPU utilization policy that allows the autoscaler to scale based on the average CPU utilization of a managed instance group.

autoscalingPolicy.cpuUtilization.utilizationTarget

number

The target CPU utilization that the autoscaler should maintain. Must be a float value in the range (0, 1]. If not specified, the default is 0.6.

If the CPU level is below the target utilization, the autoscaler scales down the number of instances until it reaches the minimum number of instances you specified or until the average CPU of your instances reaches the target utilization.

If the average CPU is above the target utilization, the autoscaler scales up until it reaches the maximum number of instances you specified or until the average utilization reaches the target utilization.

autoscalingPolicy.customMetricUtilizations[]

object

Configuration parameters of autoscaling based on a custom metric.

autoscalingPolicy.customMetricUtilizations[].metric

string

The identifier (type) of the Stackdriver Monitoring metric. The metric cannot have negative values.

The metric must have a value type of INT64 or DOUBLE.

autoscalingPolicy.customMetricUtilizations[].filter

string

A filter string, compatible with a Stackdriver Monitoring filter string for TimeSeries.list API call. This filter is used to select a specific TimeSeries for the purpose of autoscaling and to determine whether the metric is exporting per-instance or per-group data.

For the filter to be valid for autoscaling purposes, the following rules apply:

You can only use the AND operator for joining selectors.

You can only use direct equality comparison operator (=) without any functions for each selector.

You can specify the metric in both the filter string and in the metric field. However, if specified in both places, the metric must be identical.

The monitored resource type determines what kind of values are expected for the metric. If it is a gce_instance, the autoscaler expects the metric to include a separate TimeSeries for each instance in a group. In such a case, you cannot filter on resource labels.

If the resource type is any other value, the autoscaler expects this metric to contain values that apply to the entire autoscaled instance group and resource label filtering can be performed to point autoscaler at the correct TimeSeries to scale upon. This is called a per-group metric for the purpose of autoscaling.

If not specified, the type defaults to gce_instance.

You should provide a filter that is selective enough to pick just one TimeSeries for the autoscaled group or for each of the instances (if you are using gce_instance resource type). If multiple TimeSeries are returned upon the query execution, the autoscaler will sum their respective values to obtain its scaling value.

autoscalingPolicy.customMetricUtilizations[].utilizationTarget

number

The target value of the metric that autoscaler should maintain. This must be a positive value. A utilization metric scales number of virtual machines handling requests to increase or decrease proportionally to the metric.

For example, a good metric to use as a utilizationTarget is www.googleapis.com/compute/instance/network/received_bytes_count. The autoscaler will work to keep this value constant for each of the instances.

autoscalingPolicy.customMetricUtilizations[].singleInstanceAssignment

number

If scaling is based on a per-group metric value that represents the total amount of work to be done or resource usage, set this value to an amount assigned for a single instance of the scaled group. Autoscaler will keep the number of instances proportional to the value of this metric, the metric itself should not change value due to group resizing.

A good metric to use with the target is for example pubsub.googleapis.com/subscription/num_undelivered_messages or a custom metric exporting the total number of requests coming to your instances.

A bad example would be a metric exporting an average or median latency, since this value can't include a chunk assignable to a single instance, it could be better used with utilizationTarget instead.

autoscalingPolicy.customMetricUtilizations[].utilizationTargetType

enum

Defines how target utilization value is expressed for a Stackdriver Monitoring metric. Either GAUGE, DELTA_PER_SECOND, or DELTA_PER_MINUTE.

autoscalingPolicy.loadBalancingUtilization

object

Configuration parameters of autoscaling based on load balancer.

autoscalingPolicy.loadBalancingUtilization.utilizationTarget

number

Fraction of backend capacity utilization (set in HTTP(S) load balancing configuration) that autoscaler should maintain. Must be a positive float value. If not defined, the default is 0.8.

zone

string

[Output Only] URL of the zone where the instance group resides (for autoscalers living in zonal scope).

region

string

[Output Only] URL of the region where the instance group resides (for autoscalers living in regional scope).

selfLink

string

[Output Only] Server-defined URL for the resource.

status

enum

[Output Only] The status of the autoscaler configuration.

statusDetails[]

object

[Output Only] Human-readable details about the current state of the autoscaler. Read the documentation for Commonly returned status messages for examples of status messages you might encounter.

statusDetails[].message

string

The status message.

statusDetails[].type

enum

The type of error returned.

kind

string

[Output Only] Type of the resource. Always compute#autoscaler for autoscalers.

Response body

If successful, the response body contains data with the following structure:

[Output Only] An optional progress indicator that ranges from 0 to 100. There is no requirement that this be linear or support any granularity of operations. This should not be used to guess when the operation will be complete. This number should monotonically increase as the operation progresses.

insertTime

string

[Output Only] The time that this operation was requested. This value is in RFC3339 text format.

startTime

string

[Output Only] The time that this operation was started by the server. This value is in RFC3339 text format.

endTime

string

[Output Only] The time that this operation was completed. This value is in RFC3339 text format.

error

object

[Output Only] If errors are generated during processing of the operation, this field will be populated.

error.errors[]

object

[Output Only] The array of errors encountered while processing this operation.

error.errors[].code

string

[Output Only] The error type identifier for this error.

error.errors[].location

string

[Output Only] Indicates the field in the request that caused the error. This property is optional.

error.errors[].message

string

[Output Only] An optional, human-readable error message.

warnings[]

object

[Output Only] If warning messages are generated during processing of the operation, this field will be populated.

warnings[].code

enum

[Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.

warnings[].message

string

[Output Only] A human-readable description of the warning code.

warnings[].data[]

object

[Output Only] Metadata about this warning in key: value format. For example:

"data": [ { "key": "scope", "value": "zones/us-east1-d" }

warnings[].data[].key

string

[Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).

warnings[].data[].value

string

[Output Only] A warning data value corresponding to the key.

httpErrorStatusCode

number

[Output Only] If the operation fails, this field contains the HTTP error status code that was returned. For example, a 404 means the resource was not found.

httpErrorMessage

string

[Output Only] If the operation fails, this field contains the HTTP error message that was returned, such as NOT FOUND.

selfLink

string

[Output Only] Server-defined URL for the resource.

region

string

[Output Only] The URL of the region where the operation resides. Only applicable when performing regional operations.

description

string

[Output Only] A textual description of the operation, which is set when the operation is created.